iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone 6, released on 2019-01-22T18:10:27Z. The update package is 1.35 GB. This is a delta (partial) update that requires 11.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5ff3c416b3775c1b2eb68ce58aa0f13ce48a86e5.zip.